【地域資源開発学科】中鎖脂肪酸含有リン脂質を合成

Yukihiro Yamamoto, Katsumasa Tanaka, Hiroto Sugiyama, Ryota Noboritate

PC from soybean and C10:0 were subjected to lipase-mediated acidolysis/interesterification for the preparation of PC containing C10:0 (C10:0-PC). Free fatty acid form of C10:0 was selected as the best acyl donor in comparison to triacylglycerol from of C10:0 and ethyl ester from of C10:0 because higher C10:0-PC yield (46.2 ± 1.8 mol%) was obtained when free fatty acid form of C10:0 was used as acyl donor while that of triacylglycerol and ethyl ester were 24.9 ± 3.1 mol% and N.D., respectively in a preliminary reaction condition. In addition, Novozym® 435 was selected as the best catalyst compared to the commercial lipases Lipozyme® TL IM, Lipozyme® RM IM and Lipase OF® because the highest C10:0-PC yield (46.2 ± 1.8 mol%) was obtained when Novozym® 435 was used as a catalyst in a preliminary reaction condition. The reaction was then optimized based on the evaluation of acyl ratio (C10:0/PC), solvents, and reaction time, with mainly pursing C10:0-PC yield. It was demonstrated that high levels of acyl ratio decrease C10:0-incorporation, that solvents having low polarity are more effective in this reaction, and that the hydrolysis reaction was superior to the acidolysis reaction at the early stage of the process. Finally, C10:0-PC yield of 61.8 ± 3.0 mol% was obtained in the optimum reaction conditions, In this reaction system, Novozym® 435 showed regiospecificity at the sn-1 position of the PC molecule.

山本准教授らの研究グループは、中鎖脂肪酸とよばれる体脂肪軽減作用を有する脂肪酸に注目し、これをリパーゼという酵素を用いて、リン脂質の形に変換する方法について報告しました。基質の種類や反応溶媒が反応収率に大きな影響を与えること、また、リパーゼの特殊な位置選択性について明らかにしました。